This invention relates to tissue fixation devices and methods for tissue repair.
Fibrous tissues, such as ligaments and tendons, can detach from bone. The detachment can be repaired using sutures. It is known to fix a fibrous tissue to bone by inserting a suture anchor through the fibrous tissue and into the bone and knotting suture attached to the anchor to tie down the fibrous tissue to the bone. Tying suture knots in minimally invasive surgical procedures commonly requires a skilled surgeon and/or specialized equipment.
According to one aspect of the invention, a bone anchor includes an anchor body configured to be retained within bone and to selectively restrict movement of a flexible member coupled to the bone anchor such that after implantation, the flexible member can be moved through the anchor body in a first direction while, without the aid of an enlarged portion on the flexible member, e.g., a knot, movement in a second, opposite direction can be restricted.
Embodiments of this aspect of the invention may include one or more of the following features. The bone anchor includes a restrictor configured to engage the flexible member to selectively restrict movement of the flexible member. The restrictor is configured to engage the flexible member at a substantially arbitrary position along a length of the flexible member. The anchor body defines an opening through which the flexible member can be moved, and the restrictor is configured to engage the flexible member to selectively restrict passage of the flexible member through the opening. The restrictor defines at least a part of the opening, for example, a narrower portion of the opening than another portion of the opening.
In an illustrated embodiment, the restrictor includes a sloped surface configured to compress the flexible member to permit passage of the flexible member through the opening, and opposing edges for engaging the flexible member to limit passage of the flexible member through the opening.
The bone anchor includes a second restrictor configured to engage the flexible member to selectively restrict passage of the flexible member through the opening. The restrictors are oppositely directed.
The anchor body includes a pair of legs, a bone-engaging ridge for retaining the bone anchor in a bone hole, and a post about which the flexible member is positionable. The anchor body is a unitary body.
According to another aspect of the invention, a tissue repair system includes a first anchor body including a member that engages bone to retain the anchor within the bone and a second anchor body including a member that engages bone to retain the anchor within the bone. The anchor bodies each define an opening for receiving suture and a restrictor forming a one-way passage through the opening. The anchor bodies are coupled by a suture extending through the one-way passages.
According to another aspect of the invention, a bone anchor includes an anchor body configured to be retained within bone and to receive a flexible member such that after implantation of the anchor body within bone, the flexible member can be moved through the anchor body while, without the aid of an enlarged portion on the flexible member, subsequent movement of the anchor body can be restricted.
According to another aspect of the invention, a tissue repair system includes a flexible member, and first and second bone anchors coupled together by the flexible member. Each bone anchor includes an anchor body configured to be retained within bone. At least one of the bone anchors is configured to receive the flexible member such that the flexible member can be pulled to shorten a length of the flexible member between the bone anchors, while, without the aid of an enlarged portion on the flexible member, subsequent lengthening of the flexible member between the bone anchors can be restricted.
According to another aspect of the invention, a bone anchor includes an anchor body configured to be retained within bone. The anchor body defines a one-way passage configured to pass a suture in a first direction and restrict passage of the suture in a second direction opposite the first direction.
According to another aspect of the invention, a bone anchor includes an anchor body configured to be retained within bone. The anchor body includes a restrictor defining an opening having a first portion for permitting passage of a member therethrough, and a second portion restricting passage of the member therethrough without the aid of an enlarged portion on the member.
According to another aspect of the invention, a method includes placing an anchor in bone, moving a flexible member through the anchor in a first direction, and restricting movement of the flexible member through the anchor in a second, opposite direction.
Embodiments of this aspect of the invention may include placing a second anchor in bone. The second anchor is coupled to the first anchor by the flexible member. The step of moving the flexible member in the first direction shortens a length of the flexible member between the anchors.
According to another aspect of the invention, a bone anchor includes an anchor body configured to be retained within bone. The anchor body includes a restrictor defining an opening having a first portion for permitting passage of a member therethrough, and a second portion restricting passage of the member therethrough. The member is movable between the first and second portions in a direction non-parallel to a direction of passage of the member through the opening.
Embodiments of this aspect of the invention may include one or more of the following features.
The restrictor includes one or more edges lining a wall of the opening. The edge is oriented obliquely to a direction of passage of the member through the opening. Some of the edges are oriented at the same oblique angle relative to the direction of passage of the member through the opening, and some of the edges are oriented parallel to each other.
A dimension of the second portion is narrower than a diameter of the member. The opening is triangular in shape. The anchor is configured such that the member is movable between the first and second portions substantially perpendicularly to a direction of passage of the member through the opening.
In an illustrated embodiment, the anchor body includes a tissue penetrating tip, and a central body member with a driver coupling. The anchor body includes one or more resilient members with sharp, proximal edges for penetrating bone tissue. The anchor body is a unitary body.
According to another aspect of the invention, a tissue repair system includes a first bone anchor with an anchor body configured to be retained within bone, and a second bone anchor with an anchor body configured to be retained within bone. A flexible member couples the first and second bone anchors. At least one of the first and second anchor bodies includes a restrictor defining an opening having a first portion for passage of the flexible member therethrough, and a second portion limiting passage of the flexible member therethrough. The flexible member is movable between the first and second portions in a direction non-parallel to a direction of passage of the member through the opening.
According to another aspect of the invention, a bone anchor includes an anchor body configured to be retained within bone. The anchor body includes a restrictor defining an opening for passage of a member therethrough. The restrictor includes an edge lining a wall of the opening oriented such that upon movement of the member through the opening in a first direction, the member is also moved non-parallel to the first direction.
Embodiments of this aspect of the invention may include the edge being oriented such that upon movement of the member through the opening in a second direction opposite the first direction, the member is also moved non-parallel to the second direction. The restrictor includes a second edge lining a wall of the opening. The second edge is oriented such that upon movement of the member through the opening in a second direction opposite the first direction, the member is also moved non-parallel to the second direction.
According to another aspect of the invention, a method includes placing an anchor in bone and moving a member between first and second portions of an opening in the anchor in a direction non-parallel to a direction of passage of the member through the opening.
Embodiments of this aspect of the invention may include one or more of the following features.
The method includes engaging the member with an edge lining the opening. Moving the member to the second portion includes moving the member in a direction substantially perpendicular to a direction moved by the member through the first portion. A second anchor coupled to the first anchor by the member is placed in the bone.
Advantages of the invention may include permitting surgeons with varying skill levels to straightforwardly reattach tissue to bone in open or closed surgical procedures. The surgeon is able to fix a fibrous tissue to bone using an appropriate tension simply by pulling a suture received by the bone anchor in a first direction. Since the bone anchors of the present invention limit subsequent movement of the suture in the opposite direction, the surgeon is able to easily select the appropriate tension.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.